The synthesis, characterization, and reactivity toward ethylene of pyridinecarboxamidato complexes of nickel are reported. These compounds are isoelectronic to α-iminocarboxamidato complexes, which are useful ethylene polymerization catalysts. Addition of a benzene solution containing N-phenyl-2-pyridinecarboxamide and B(C₆F₅)₃ to bis(methallyl)nickel results in the formation of [N-phenyl-2-pyridinecarboxamidatotris(pentafluorophenyl)borate-κ²N,N]Ni(η³-CH₂CMeCH₂) (3) in 93% yield. A similar procedure using N-(2,6-diisopropyl)phenyl-2-pyridinecarboxamide provides [N-(2,6-diisopropyl)phenyl-2-pyridinecarboxamidatotris(pentafluorophenyl)borate-κ²N,N]Ni(η³-CH₂CMeCH₂) (4) in 92% yield. The solid-state structures of 3 and 4 were determined by X-ray diffraction techniques. The intramolecular metrical parameters are consistent with substantial partial positive charge at the nickel atom. Deprotonation of N-(2,6-diisopropyl)phenyl-2-pyridinecarboxamide in THF with KH, followed by addition to Ni(η³-CH₂C₆H₅)Cl(PMe₃) and subsequent treatment with 2 equiv of B(C₆F₅)₃, produces [N-(2,6-diisopropyl)phenyl-2-pyridinecarboxamidatotris(pentafluorophenyl)borate-κ²N,N]Ni(η³-CH₂C₆H₅) (5). Compound 5 is obtained as a mixture of isomers. Deprotonation of N-(2,6-diisopropylphenyl)-6-triisopropylsilyl-2-pyridinecarboxamide, followed by addition to Ni(η³-CH₂C₆H₅)Cl(PMe₃), gives a product (7) which lacks a benzyl fragment. An X-ray diffraction study shows that metalation of one of the isopropyl groups and loss of the benzyl ligand takes place. The reactivity of 3, 4, 5, and 7 toward ethylene is presented. Considerably more activity is obtained with 5, probably as a result of faster initiation. The pyridine ligand leaves an open quadrant adjacent to nickel. As a result, the molecular weight of the product is not high.

中文翻译：

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吡啶甲酰胺基-镍（II）配合物

报道了镍的吡啶甲酰胺基络合物的合成，表征和对乙烯的反应性。这些化合物与α-亚氨基羧酰胺配合物是等电子的，α-亚氨基羧酰胺配合物是有用的乙烯聚合催化剂。含有的苯溶液中加入ñ -苯基-2-吡啶羧酰胺和B（C ₆ ˚F ₅）₃，以双（甲代烯丙基）镍导致的[形成Ñ苯基-2- pyridinecarboxamidatotris（五氟苯基）硼酸盐-κ ² Ñ，ñ ]镍（η ³ -CH ₂ CMeCH ₂）（3），收率93％。使用N的类似过程- （2,6-二异丙基）苯基-2-吡啶羧酰胺提供[ Ñ - （2,6-二异丙基）苯基-2- pyridinecarboxamidatotris（五氟苯基）硼酸盐-κ ² Ñ，Ñ ]镍（η ³ -CH ₂ CMeCH ₂） （4）产率为92％。通过X射线衍射技术确定3和4的固态结构。分子内的度量参数与镍原子上的基本部分正电荷一致。去质子化ñ - （2,6-二异丙基）苯基-2-吡啶甲酰胺在THF中与KH，然后加入到镍（η ³ -CH ₂ C ^ ₆ ħ₅）氯（PME ₃），随后用2当量B（C的治疗₆ ˚F ₅）₃，产生[ Ñ - （2,6-二异丙基）苯基-2- pyridinecarboxamidatotris（五氟苯基）硼酸盐-κ ² Ñ，Ñ ]的Ni（η ³ -CH ₂ C ^ ₆ ħ ₅）（5）。获得作为异构体混合物的化合物5。去质子化ñ - （2,6-二异丙基）-6-三异丙基硅烷基-2-吡啶甲酰胺中，随后加入到镍（η ³ -CH ₂ C ^ ₆ ħ ₅）Cl（PMe ₃），得到缺乏苄基片段的产物（7）。X射线衍射研究表明，发生了异丙基之一的金属化和苄基配体的损失。的反应性3，4，5，和7朝向乙烯被呈现。5可能获得更多的活性，这可能是由于更快的引发作用所致。吡啶配体在镍附近留下一个开放的象限。结果，产物的分子量不高。